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Principles of fracture fixation Josefa Bizzarro, Pietro Regazzoni How to use this handout? The left column is the information as given during the lecture. The column at the right gives you space to make personal notes. Learning outcomes At the end of this lecture you will be able to:

Outline the four principles of fracture fixation

The four AO principles The four AO principles of fracture fixation are 1. Fracture reduction to restore anatomical

relationships.

2. Fracture fixation providing absolute or relative stability as the personality of fracture, patient and injury requires.

3. Preservation of blood supply to soft tissues and

bone. 4. Early and safe mobilization of the injured part and

the patient as a whole.

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1. Fracture reduction

What does fracture reduction mean? There are two forms of displacement:

Translational displacement: 1. Medial or lateral and posterior or anterior 2. Shortening or lengthening

Rotational displacement: 1. Internal or external

rotational malaligment

2. Valgus or varus malaligment

3. Flexion or extension

malalignment

Why fracture reduction? Example 1

On the x-rays we can see a fracture fixed with an intramedullary nail that looks reduced on the lateral view. On the AP view however we can see that there is some valgus angulation of the distal fragment.

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Example 2 This fracture was not treated operatively and has healed with varus, antecurvatum, and shortening malunion.

Aim of reduction Some fractures are reduced to restore 1. the bony anatomy and morphology. Perfect or

anatomical reduction is required.

2. the relationship between the proximal and distal main fragments. Length, alignment and rotation are restored. This is functional reduction.

Reduction methods The decision, which reduction method should be used, depends on the location of the fracture:

1. Meta- and diaphyseal fractures usually need functional reduction.

2. Joint fractures need anatomical reduction.

Reduction of diaphyseal fractures The functional anatomy is restored

(length, alignment, and rotational axis).

The load-bearing axis of the extremity is restored (especially important in the lower limb).

An exception is the forearm which

functions as a single articular unit. Forearm

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Reduction of articular fractures The joint surface is

restored anatomically. Gaps and steps in the articular surface must be avoided. Steps means

that there is a difference between the levels of two main articular fragments.

Gaps means that there is some space between two adjacent main articular fragments.

The axial alignment is restored.

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2. Fracture fixation

What does fracture fixation mean? Goal of fracture fixation 1. To maintain the reduction

2. To create adequate stability which:

Allows early and optimal function of the injured limb

Minimizes pain

The main goal of internal fixation is to achieve prompt and, if possible, full function of the injured limb. Although reliable fracture healing is only one element in functional recovery, its mechanics, biomechanics, and biology are essential for a good outcome.

Absolute stability There is no movement at fracture site.

It is achieved by interfragmentary compression, eg.

lag screws, compression plate

There is no callus formation. Direct bone healing is

achieved.

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When is absolute stability required? How is absolute stability achieved? Which fixation techniques are used? Relative stability Movement at fracture site

There is no interfragmentary compression

at fracture site. It is achieved by splinting or bridging, eg. elastic nails

There is callus formation. Indirect bone

healing is achieved.

When is relative stability required? How is relative stability achieved? Which fixation techniques are used?

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3. Preservation of blood supply

To what does "Preservation of blood supply" refer to? Care for the soft tissues Evaluation of limb swelling

Consideration for staged procedure is important:

Primary stabilization external fixation Secondary stabilization definitive fixation

Careful reduction procedure

Too intense efforts for perfect reduction are

risky Increases infection rate

Minimal invasive surgery

Example 42y-old-man with a humerus fracture after a gun shot

Courtesy of: C Sommer

Nursing care of patient with fractures Care during transfer and positioning

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Taking care of body temperature In old and young patients During long surgeries

Intraoperative nursing care Use of atraumatic soft-tissue forceps and

retractors

Reduce pressure on bone elevators

Irrigate wound regularly

Cover wound with wet pads

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4. Preservation of blood supply

What does this mean? Postoperative care Immediately after surgery

Elevation of the limb

Immediately after the operation, the treated extremity is positioned above the level of the heart to minimize swelling. Following osteosynthesis of the upper extremity, the limb is either placed on a cushion or elevated in a bag. When the latter is used, flexion of the elbow should not exceed 75. After any procedure, pressure, malpositioning, and deformity must be prevented. In particular, the medial epicondyle of the elbow (ulnar nerve) and the head of the fibula (fibular nerve) must be well padded. During follow-up treatment, not only look at the x-rays but also at the injured limb. Pain, swelling, and tenderness are signs of either instability or infection.

Early joint motion: Use of CPM machines

CPM (continuous passive motion) machines are used to provide a continuous but passive (without force of the patient) motion for limbs where after

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surgery (knee or elbow) stiffness of the limb might be expected. Partial weight bearing

Adequate pain control

Thrombosis prophylaxis

Early recognition of complications

Postoperative management is not limited to the time spent in hospital, but must be carried on at home, at work and during leisure and sport. To achieve this three postoperative phases are recognized: 1. Immediately after surgery emphasis is on pain

control, mobilization, thrombosis prophylaxis, and early recognition of complications.

2. When the patient leaves the hospital, attention is centered upon integration into the home and into the professional and social environment. Good mobilization is important.

3. Treatment is finished. The patient returns to his/her

preoperative capabilities.

Summary

You should now be able to:

Outline the four principles of fracture fixation

Questions 1. What type of reduction is performed here?

2. What type of stability is required here?

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3. The patient has a forearm fracture and blisters on the skin. What to do next? Answers on in-course questions 1. Fracture reduction

Question 1What does fracture reduction mean? Reduction is the action of restoring a dislocation or fracture by returning the affected part of the body to its normal position.

Question 2What does fracture fixation mean? The fracture is fixed providing absolute or relative stability as the personality of the fracture, the patient and the injury requires.

2. Fracture fixation

Absolute stability Question 1When is absolute stability required? Important indications for absolute stability are articular fractures. Question 2How is absolute stability achieved? It is achieved by interfragmentary compression. Question 3Which fixation techniques are used? Lag screws Compression plates Tension band

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Relative stability Question 1When is relative stability required? Important indications for relative stability are diaphyseal fractures. Question 2How is relative stability achieved? It is achieved by splinting or bridging. Question 3Which fixation techniques are used?

Intramedullary nailing Internal fixator External fixation

3. Preservation of blood supply Question 1To what does "Preservation of blood supply" refer to?

Handling and care of patient with fractured bone(s): Decontamination of fracture site Positioning of fractured limb

Perioperative care of the soft tissues Vessels, muscles

4. Early mobilization

Question 1"Early mobilization" what does this mean? This means mobilization of the injured part and the patient as a whole.